Cryostat for cutting flash-frozen tissue sections

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The equipment requested is a Leica cryostat for cutting of thin sections of previously rapidly-frozen tissue. A major part of Gardiner's NSERC-funded research involves determining the level of proteins, and of the messenger RNAs which code for these proteins, in the neurons in rats which control the hindlimb muscles, the alpha-motoneurons. Another research direction involves measuring the effects of obesity and diabetes in rats on blood flow and its regulation in a variety of different tissues. In both cases, tissues removed from the rat must be rapidly frozen, and later sectioned at a temperature of about minus 20 degrees C, to treat the tissues subsequently to visualize the elements we are interested in. Stecina's NSERC-funded research program involves the identification of spinal interneurons and their functional networks in the adult rodent nervous system. In almost all of those experiments, in addition to the electrophysiological studies, verification of the placement of stimulation electrodes in the brain is required post-hoc. Also, for the electrophysiological characterization of interneuronal networks, neuroanatomical methods, such as activity dependent labelling, identification of recording sites in the spinal cord are also used practically after each of the performed experiment. In addition, the cutting of thin sections from spinal cord and brain tissue harvested after each electrophysiological experiment warrants the use of a cryostat on a frequent basis (minimum 1 - 2 days per week). For Cowley, NSERC-funded investigations of the neural basis of stepping and balance require the use of a cryostat for lesion verification, studies involving retrograde labeling of interneurons and motoneurons, as well as for immunohistochemistry related to the neurotransmitter receptor distribution. We currently use a cryostat that is 15 years old, which is heavily used, and is breaking down. The purchase of the requested equipment will allow all of these research programs, which have implications for our understanding of how we move, how the neural networks involved in movements are controlled by higher centres and how the environment influences the gene expression and function of nervous and other tissues, to continue without interruption. When the currently-used cryostat ceases to function properly, which we expect will occur at any time due to its age, the unavailability of replacement parts, and current heavy usage, the research programs of the three investigators will be severely compromised, such that entire portions of their respective research programs will be impossible to complete.